A modern, scalable, robust DHCPv4 and DHCPv6 server, with database (MySQL, PostgreSQL), hooks, multi-threading, RADIUS, NETCONF, Kerberos and more.

Java library for handling IP addresses and subnets, both IPv4 and IPv6

IPv6 address rate limiting evasion tool (that also supports IPv4)

radvd | Official repository: https://github.com/radvd-project/radvd

A library for working with IP addresses and networks in Go

IP/IPv6 to region on Node.js （IP/IPv6 地址到区域运营商）

High-performance match IP address for Nginx + Lua

IPv4 and IPv6 traceroute fake hop generator through IP spoofing

Collecting Tor Bridges.

Go library for handling IP addresses and subnets, both IPv4 and IPv6

IP Address utility classes for PHP

Fast Java library for working with IP addresses, ranges, and subnets

ipv6calc

IPv6 prefix generator

IPv6 Subnet Calculator / Tool application lets you plan/subnet your assigned IPv6 address for all 128 bits.

A system administration related project

中国大陆IPv6地址库（北京时间每日6:00自动构建）

IPv6-adresse.dk source & data

A browser extension, which shows you the origin of your IP address.